1. Field of the Invention
This invention relates to an aqueous preparation comprising a compound (A) represented by the formula: ##STR2## and at least one of cyclodextrins selected from .alpha.-cyclodextrin and dimethyl-.beta.-cyclodextrin; and a method of preparation thereof.
2. Description of Prior Art
The aforesaid compound (A) is known to be a selective inhibitor for 5-riboxygenase which is one of important metabolism enzymes for arachidonic acid cascade and to inhibit the production of SRS-A or LTB.sub.4, showing experimental allergic asthma which IgG and IgE in Guinea pigs or IgE in rats partake.
In view of the strong anti-allergy action of compound (A), an attempt has been made to develop it as a medicament. However, its solubility is too small to obtain an aqueous solution having a concentration sufficient to exhibit pharmacological effect and consequently, clinical application as an aqueous preparation, such as oral drug, injection drug, nose drops (rhinenchysis drug), eye drops, etc., is expected, but not yet realized in practice.
In local administration of this compound as a liquid preparation, such as a nose drops or eye drops, its concentration is generally required to be from 0.1 to 3 mg/ml.
The compound (A), however, has an extremely low solubility to water, for example, only showing a slight solubility (in the order of less than 10 ng/ml at 25.degree. C.), so that its application as a liquid preparation was regarded as extremely difficult.